Abstract : The central objective of this research program has been to study theoretically the underlying principles of quantum transport in solids. The area of research investigated has emphasized the understanding of two electron processes in quantum transport. The problems have been treated analytically to the extent possible through the use of dynamical localized Wannier functions. These results have been and are being incorporated in a full quantum transport theory that includes dielectric screening, dynamical high-field effects, and electron electron interactions. The research under this grant has culminated in the formulation of a theory describing Bloch electron transport in inhomogeneous electric fields due to localized impurities. Based on this model, a variety of novel field controlled current modulators have been defined; the U.S. Army has filed for a patent based on these concepts.